/* Hard
A move consists of taking a point (x, y) and transforming it to either (x, x+y) or (x+y, y).

Given a starting point (sx, sy) and a target point (tx, ty),
return True if and only if a sequence of moves exists to transform the point
(sx, sy) to (tx, ty). Otherwise, return False.

Examples:
Input: sx = 1, sy = 1, tx = 3, ty = 5
Output: True
Explanation:
One series of moves that transforms the starting point to the target is:
(1, 1) -> (1, 2)
(1, 2) -> (3, 2)
(3, 2) -> (3, 5)

Input: sx = 1, sy = 1, tx = 2, ty = 2
Output: False

Input: sx = 1, sy = 1, tx = 1, ty = 1
Output: True

Note:
sx, sy, tx, ty will all be integers in the range [1, 10^9]. */


class Solution {
public:
    bool reachingPoints(int sx, int sy, int tx, int ty) {
        while (sx < tx && sy < ty) {
            if (ty > tx) {
                ty %= tx;
            } else {
                tx %= ty;
            }
        }

        if (sx > tx || sy > ty)
            return false;

        return (sx == tx) ? ((ty - sy) % sx == 0) : ((tx - sx) % sy == 0);
    }
};